1. Field of the Invention
The present invention relates to a water base ink for ink-jet recording, an ink cartridge, and an ink-jet recording apparatus.
2. Description of the Related Art
In recent years, a high printing speed, which is equivalent to that of a laser printing, is required to be realized in the printing on a plain paper in the field of the ink-jet printing. A method, in which the printing dot number is decreased for the plain paper to enhance the permeability of the ink, is exemplified as a method for achieving the realization of the high printing speed.
The permeability of the ink can be enhanced by adding a penetrant to the ink. For example, an ink has been suggested, in which diethylene glycol n-hexyl ether (DEGHE) is used as the penetrant (Japanese Patent Application Laid-open Nos. 1-266173, 3-14881, 4-153279, 8-67840, 11-166144, 11-256087, and 11-181341 and International Publication No. WO 00/04103).
However, if a large amount of DEGHE is added to the ink, the vaporization characteristic of the ink is deteriorated. For this reason, before the ink is discharged from an ink-jet head, the ink is solidified and/or the coloring agent in the ink precipitates or aggregates, for example, on an ink-discharge surface of the ink-jet head and/or on a wall surface of an ink tank, consequently making the nozzle of the ink-jet head easily clog-up, thus causing the discharge failure or undischarge.